AP Chemistry periodic trends flashcards

What is atomic radius?

The distance from the nucleus to the outermost electron cloud.

True or false: Atomic radius increases down a group.

True, because additional electron shells are added.

Define ionization energy.

The energy required to remove an electron from an atom in the gas phase.

Which element has the highest electronegativity?

Fluorine (F), with a value of 3.98 on the Pauling scale.

Difference between ionization energy and electronegativity.

Ionization energy measures energy needed to remove an electron; electronegativity measures an atom's ability to attract electrons.

What is electronegativity?

A measure of an atom's attraction for electrons in a chemical bond.

Fill in the blank: Electronegativity generally _____ across a period.

increases

True or false: Metals have high ionization energies.

False, because metals typically have low ionization energies.

What is the trend of atomic radius across a period?

It decreases as the number of protons increases, attracting electrons more strongly.

Define electron affinity.

The change in energy when an electron is added to a neutral atom in the gas phase.

Which has a larger atomic radius: Na or Cl?

Sodium (Na); it has fewer protons and a larger radius.

True or false: Electron affinity becomes more negative across a period.

True, because atoms become more eager to gain electrons.

What is the trend of metallic character down a group?

It increases as atoms become larger and lose electrons more easily.

Which group has the highest ionization energies?

Noble gases, due to their full valence shell.

Fill in the blank: Ionization energy generally _____ down a group.

decreases

What is shielding effect?

The reduction in effective nuclear charge on the electron cloud due to other electrons.

Which has a higher electronegativity: O or N?

Oxygen (O); it is more effective at attracting electrons than nitrogen.

True or false: Nonmetals have higher electron affinities than metals.

True, because nonmetals tend to gain electrons.

Difference between first and second ionization energy.

First ionization energy is for removing the first electron; second is for removing the second, which is always higher.